1. Field of the Invention
The present invention relates to methods for separating a composite composed of at least a substrate and a member fixed thereon by a shearing force applied by a pair of blades.
2. Description of the Related Art
In order to simplify manufacturing processes and to reduce manufacturing costs thereof, in a process for manufacturing products, a method for forming a plurality of products by separating a composite composed of a substrate and various elements provided thereon has been generally carried out.
As methods for separating a composite, various methods such as mechanical shearing, cutting, laser radiation, and water jet, have been well known. Among the various methods mentioned above, mechanical shearing, having a high separation speed and being performed at a low cost, has been widely used.
As a related technique for separating a composite by mechanical shearing, for example, a technique disclosed in Japanese Patent Laid-Open No. 10-335688 may be mentioned. A separation process according to the technique of Japanese Patent Laid-Open No. 10-335688 is shown in FIG. 12 by way of example. Numerals 1 to 4 shown on the left side of FIG. 12 indicate sequential steps of separating a composite 1003. Steps 1 to 4 are shown by cross-sections of the composite 1003 viewed from the front surface (on the left side of FIG. 12) and from the side surface (on the right side of FIG. 12). In the figure, the front surface (on the left side of FIG. 12) is a cross-sectional view of the side surface (on the right side of FIG. 12) taken along the line B–B′, and the side surface (on the right side of FIG. 12) is a cross-sectional view of the front surface (on the left side of FIG. 12) taken along the line A–A′.
Step 1 in FIG. 12 shows the state in which a thin semiconductor layer (not shown) is formed on an upper surface of a substrate 1001, a first member 1002 made of a thin metal wire is further fixed onto the upper surface of the substrate 1001 with an insulating material 1006 provided therebetween to form a composite 1003, and in which this composite 1003 is placed on a first rigid body 1004 having a horizontal surface 10042 and a horizontal linear edge 10041, which is an edge thereof.
Furthermore, Steps 2 to 4 in FIG. 12 show the states in which a second rigid body 1005 is moved down from above, and in which the composite 1003 is mechanically separated by a shearing force applied thereto by the first rigid body 1004 and the second rigid body 1005.
A method for placing the composite 1003 on the first rigid body 1004 has not been disclosed in Japanese Patent Laid-Open No. 10-335688; however, a known method as shown in FIG. 8 may be easily employed. Numerals 1 and 2 on the left side of FIG. 8 indicate sequential steps of placing a composite 603 on a horizontal surface 6042 of a first rigid body 604. Steps 1 and 2 are shown by cross-sections of the composite 603 viewed from the front and the side surfaces thereof. In Step 1 shown in FIG. 8, the composite 603 is placed on a stage 612 having a horizontal surface 6121 connected flush with the horizontal surface 6042 so as to be in contact with a pusher 613. Furthermore, in Step 2 shown in FIG. 8, the composite 603 is slid on the horizontal surfaces 6121 and 6042 by the pusher 613, thereby placing the composite 603 on the first rigid body 604. In the method described above, by only controlling the pusher 613, the position at which the composite 603 thus slid is to be stopped can be easily controlled with good reproducibility. Hence, the size of the composite 603 after separation can be controlled with good accuracy, and from this point of view, this technique is superior. In addition, when the apparatus shown in FIG. 8 is manufactured, the number of movable parts is small, and hence this technique is also superior in terms of manufacturing cost.
In addition, as a related technique 2, a technique disclosed in Japanese Patent Laid-Open No. 8-103910 may be mentioned. One example of a separation process according to Japanese Patent Laid-Open No. 8-103910 is shown in FIG. 4. Numerals 1 to 4 shown on the left side of FIG. 4 indicate sequential steps of separating a composite 203. Steps 1 to 4 are shown by cross-sections of the composite 203 viewed from the front surface (on the left side of FIG. 4) and from the side surface (on the right side of FIG. 4). Step 1 in FIG. 4 shows the state in which the composite 203 provided with a printed circuit pattern (not shown), mounted elements (not shown), and the like is placed on a conveyor system composed of a tray 210, cylinders 208, support tables 209, and wheels 207. Next, in Step 2 shown in FIG. 4, the composite 203 is inserted between a first rigid body 204 and a second rigid body 205 by moving the conveyor system. This first rigid body 204 has a horizontal linear edge 2041 at the topmost position. Furthermore, in Step 3 shown in FIG. 4, by moving the cylinders 208 down, the composite 203 is moved down so as to be brought into contact with the horizontal linear edge 2041 of the first rigid body 204. Finally, as shown in Step 4 in FIG. 4, by moving the second rigid body 205 down, a shearing force is applied to the composite 203 by the first and the second rigid bodies 204 and 205, thereby separating the composite 203.
However, the related techniques described above have the following problems.
In the separation method according to Japanese Patent Laid-Open No. 10-335688, as shown in FIG. 6, when a composite has the structure in which a first member 402 is fixed onto a part of a bottom surface 4011 of a substrate 401, that is, when the composite has a first region 40111 provided with the first member 402 thereon and a second region 40112 provided with no first member 402, and when the first region 40111 and the second region 40112 are simultaneously separated, the substrate is liable to be deformed or is liable to be damaged.
FIG. 5 shows a separation process in which a composite 303 having a substrate 301 provided with a first member 302 and a second member 306 on the bottom and the top surfaces, respectively, is fixed by a first rigid body 304 and a second rigid body 305, which are equivalent to those in Japanese Patent Laid-Open No. 10-335688, and subsequently, the substrate 301 and the first member 302 are simultaneously separated. Numerals 1 to 4 on the left side of FIG. 5 indicate individual steps of the separation process described above. Steps 1 to 4 are shown by cross-sections of the composite 303 viewed from the front surface (on the left side of FIG. 5) and from the side surface (on the right side of FIG. 5). In the figure, the front surface (on the left side of FIG. 5) is a cross-sectional view of the side surface (on the right side of FIG. 5) taken along the line B–B′, and the side surface (on the right side of FIG. 5) is a cross-sectional view of the front surface (on the left side of FIG. 5) taken along the line A–A′.
Step 1 in FIG. 5 shows the state in which the composite 303 is placed on the first rigid body 304 having a horizontal surface 3042 and a horizontal linear edge 3041 which is an edge thereof. In addition, Steps 2 to 4 show the states in which by moving the second rigid body 305 down, the composite 303 is mechanically separated by a shearing force applied thereto by the first rigid body 304 and the second rigid body 305. As shown in the front view of Step 2, a gap is present between the first rigid body 304 and the substrate 301. In addition, as shown in the side view of Step 2, since the horizontal surface 3042 is present, the first member 302 cannot escape downward. According to the situations described above, as shown in the front view of Step 3 in FIG. 5, deformation of the substrate 301 occurred at a position close to the end portion of the first member 302. When the substrate was not deformed, damage such as cracks occurred in some cases. In addition, even when damage done to the substrate itself was not so serious, thin layers, circuit patterns, elements, and the like formed on the substrate were damaged in some cases, or peeling occurred between the substrate and thin layers, circuit patterns, elements, and the like in some cases.
On the other hand, when the composite as shown in FIG. 6 is separated by the separation method in accordance with Japanese Patent Laid-Open No. 8-103910, unlike the separation method according to Japanese Patent Laid-Open No. 10-335688, the deformation of the substrate or damage done thereto can be suppressed.
FIG. 7 shows a part of the separation process in the case described above. Numerals 1 to 4 shown on the left side of FIG. 7 indicate sequential steps of the separation process. Steps 1 to 4 are shown by cross-sections of a composite 503 viewed from the front surface (on the left side of FIG. 7) and from the side surface (on the right side of FIG. 7). Since a first rigid body 504 of the Japanese Patent Laid-Open No. 8-103910 has a non-horizontal surface having a horizontal linear edge 5041, as shown in the side surface views of Steps 3 and 4 in FIG. 7, the first rigid body 504 can be cut into a first member 502. Hence, the gap between a substrate 501 and the horizontal linear edge 5041 of the first rigid body 504 shown in Step 3 in FIG. 7 disappears in a process from Step 3 to Step 4 without causing any deformation of the substrate 501 or damage done thereto. That is, since the first rigid body 504 does not have a horizontal surface, the deformation of the substrate and the damage done thereto can be suppressed.
However, the separation method according to Japanese Patent Laid-Open No. 8-103910 has a problem in that the simple conveyor system for the composite 603 shown in FIG. 8 cannot be easily used. FIGS. 9 and 10 show sequential conveyor steps when the conveyor system for the composite 603 shown in FIG. 8 is applied to the separation process according to Japanese Patent Laid-Open No. 8-103910. Numerals 1 and 2 on the left side of FIG. 9 and numerals 1 to 3 on the left side of FIG. 10 indicate sequential steps of the conveyor process. The figures are views of composites 703 and 803 when viewed from the side surface. FIG. 9 shows the case in which a horizontal linear edge 7041 of a first rigid body 704 is located at a position higher than that of an upper surface 7121 of a stage 712. Unlike the case shown in FIG. 9, FIG. 10 shows the case in which a horizontal linear edge 8041 of a first rigid body 804 is located at a position lower than that of an upper surface 8121 of a stage 812.
In the case shown in FIG. 9, a substrate 701 of the composite 703 is brought into contact with the first rigid body 704 in a process from Step 1 to Step 2, and the composite 703 then runs onto the first rigid body 704. In this case, the composite 703 is liable to come away from a pusher 713, and as a result, the position at which the composite 703 is to be separated is liable to vary, thereby decreasing the accuracy in size of the composite after separation. In addition, when the substrate 701 is brought into contact with a non-horizontal surface 7043 of the first rigid body 704, deformation of the composite 703 or damage done thereto and/or damage done to the first rigid body 704 may occur with high probability.
In the case shown in FIG. 10, since the composite 803 is pushed by a second rigid body 805 moving down as shown in Step 3, deformation of the composite 803 or damage done thereto may occur at the edge of the stage 812 with high probability. Alternatively, even when the deformation or the damage does not occur, since the composite 803 is pushed down by the second rigid body 805 when it is moved down, the position at which the composite 703 is to be separated is liable to vary, and hence the accuracy in size of the composite after separation is decreased.
In order to prevent the inconveniences shown in FIGS. 9 and 10, it may be considered that the heights of the horizontal linear edges 7041 and 8041 are adjusted to be flush with the upper surfaces 7121 and 8121 of the stages 712 and 812, respectively. However, in practice, in order to prevent the composites 703 and 803 from being brought into contact with the first rigid bodies 704 and 804, respectively, in consideration of the warpage of parts of the composites 703 and 803 protruding from the respective ends of the stages 712 and 812, the horizontal linear edges 7041 and 8041 must be set at positions which are slightly lower than the upper surfaces 7121 and 8121 of the stages 712 and 812, respectively. Hence, as a result, the problem shown in FIG. 10 is liable to occur, and the adjustment of the positions described above has been difficult. In addition, since the warpage of the composites 703 and 803 varies from composite to composite, even when the adjustment is performed once, when another composite 703 or 803 is provided, the problem shown in FIG. 9 may arise in some cases, and as a result, a problem in that the yield is liable to be decrease cannot be solved.
According to the technique disclosed in Japanese Patent Laid-Open No. 8-103910, since the first rigid body 204 does not have a horizontal surface, a very complicated conveyor method as described below must be performed. That is, as shown in FIG. 4, after being placed on the conveyor system composed of the tray 210, the cylinders 208, the support tables 209, and the wheels 207, the composite 203 in this state is moved to a position between the first rigid body 204 and the second rigid body 205 by moving the conveyor system, and the cylinders 208 are then moved down so that the composite 203 is brought into contact with the horizontal linear edge 2041 of the first rigid body 204. As a result, the position at which the composite 203 is to be separated is liable to vary, and the accuracy in size of the composite after separation is disadvantageously degraded. In addition, in order to realize the complicated conveyor method as described above, the number of components is increased, and as a result, a problem in that cost reduction cannot be easily achieved still remains.